My car will be going in for a few things in a week or so -- this issue is on the list.

If it's happening often, your chances of duplicating it at the dealer's is good!

 

Same thing with me. Happening more than last year since the cold weather.
Also, now happening more than a few times, the HVAC fan stops blowing and the car throws a Dynamic Drive error then the fan comes back on.
I haven't been following anything here (however I take a peek every now and then) but it really appears to be a voltage issue.

 

I think, as we suspected, it's now clear that this problem is caused by a weak battery. I just had a new battery installed and even though it's been bitter cold, I have not seen this problem since. Before the new battery, it was happening fairly often so unless it happens again soon, I'd say that we've finally solved this issue once and for all.

Of course it still may be difficult to get this fixed since I don't think BMW has yet to recognize this problem formally. If the dealer can duplicate the problem, that's probably the first step towards resolution. Hopefully someone at BMW is reading this so that they can be ready for the next time a tech files a PuMA case about this problem...